CFD Modeling of Solid Suspension In a Stirred Tank for Pharmaceutical Application

Solid-liquid mixing is one of the most important mixing operations in pharmaceutical industry due to its vast applications in many unit operations such as crystallization, adsorption, dissolution and solid-catalyzed reaction. In this study, a computational fluid dynamics (CFD) model was developed using two fluid model for solid-liquid mixing process in a typical stirred tank reactor. The multiple reference frames (MRFs) approach was used to simulate impeller rotation in a weakly baffled reactor. The turbulent solid-liquid flow was simulated using a two-fluid Reynolds Stress Model with mixture properties. The effect of turbulent dispersion force is also taken in to account. Two different drag laws were tested. Simulation results were compared with various experimental data including cloud height and solid distribution. Parametric simulations are run at different rotational speed to calculate just suspension velocity.